A/T - New Long Lip Seal Design 3-4 and Forward Clutches

GROUP REF.: Transmission

BULLETIN NO.: 477105

DATE: March, 1994

SUBJECT:
NEW LONG LIP SEAL DESIGN 3A AND FORWARD CLUTCHES

MODELS:
1994 BUICK ROADMASTER
1994 CADILLAC FLEETWOOD
1994 CHEVROLET CAPRICE, CAMARO, CORVETTE
1994 PONTIAC FIREBIRD
1994 CHEVROLET AND GMC C/K, S/T TRUCKS AND M/L, G VANS
1994 OLDSMOBILE BRAVADA

TRANSMISSION APPLICATIONS:
1994 HYDRA-MATIC 4L60-E (RPO M30)




BULLETIN COVERS: (Figure 1)

New product information for 1994 HYDRA-MATIC 4L60-E transmissions. New clutch piston seal design. The 3-4 clutch piston outer seal and the forward clutch piston outer seals have been redesigned to include a long lip profile for enhanced sealing. Be certain to familiarize yourself with these updates to properly repair the 1994 HYDRA-MATIC 4L60-E transmission.




DATE OF PRODUCTION CHANGE: (Figure 2)

Beginning with August 09, 1993, the HYDRA-MATIC 4L60-E transmissions were built with a new 3-4 clutch outer seal (long lip). On September 20,1993 the HYDRA-MATIC 4L60-E transmissions were built with a new forward clutch outer seal (long lip).

SERVICE PARTS INFORMATION:

The new 3-4 clutch outer seal and forward clutch outer seal should be used when rebuilding transmissions that operate under -25°F or if the 3-4 clutch plates or forward clutch plates exhibit a burnt condition.

The long lip seals are interchangeable with the current seals. The new design will replace the current seal in service packages as stock is depleted. To order the long lip seals individually use the following part numbers:

PART NUMBER PART NAME

8642138 3-4 Clutch Outer Seal
8686146 Forward Clutch Outer Seal

These seals can also be used for 1982-1993 HYDRA-MATIC 4L60 and 4L60-E transmissions.

NOTE:
The GMC Bulletin No. 367106 Automatic Transmission Service Procedure, will remain in effect for GMC trucks only.

Parts are currently available from GMSPO.